The evolution of devices for self-medication has been of great advantage to sufferers of various diseases and pathologies.
One prime example is that of asthma in earlier times, sufferers of asthma were typically sentenced to a lifetime of disability, often based on arranging their life around low levels of physical activity or restricted ranges of travel, so that they could be close to support mechanisms provided in their own environment. Severe bouts of asthma often required the attention of professionals, such as doctors, and the use of drugs administered by those professionals. These drugs, which included aminophylline and adrenaline, had reasonable levels of efficiency but also brought with them some significant risks in use. Further, the use of these drugs was a late stage step in the process and did not provide any ongoing advantage to a patient in the way of control and stabilization of the disease condition.
The development of corticosteroids was of great assistance in some diseases and, in particular, asthma. However, the side effects of prolonged oral or parenteral administration of corticosteroids in people are notorious and necessitate restrictions on the adoption of this approach in other than the most severe cases.
A dramatic improvement in the quality of life of sufferers of asthma arose with the development of pressurized medicated containers designed, in part, for the self-administration of salbutamol, a bronchodialator, which is very effective in counteracting the bronchospasm of an asthma attack. Salbutamol is usually provided in a pressurized container with a depression-activated valve at its top. The valve is configured to nest in a seat provided on an outer plastic collar, cap or mouthpiece. This collar allows the depression of the canister relative to a valve stem, thereby releasing a controlled dose of therapeutic agent into a discharge throat of the collar. A patient uses the device by exhaling to a required extent and then inhaling while depressing the canister to discharge a dose of the agent.
As well as providing the ability to treat an attack of respiratory embarrassment, the salbutamol inhalers have provided the ability to self-administer a regime of treatment to thereby minimize clinical signs and allay or prevent further development of the respiratory attack.
Salbutamol is an excellent example of a suitable therapeutic agent for self-delivery but is by no means alone. Many other forms of therapy have been provided for asthma (for example, Becotide, Flexitide, Asmol). Additionally, many other diseases lend themselves to self-medication through the provision of a metered dose, either into the respiratory tract or for ingestion through the gastrointestinal tract or absorption through the mucous membranes of the oropharynx or the nose. Certain analgesics may also be provided for use in emergency situations. For instance, it is known to provide methoxyfluorane to victims of trauma, either accidental or inflicted on a battlefield.
Provision of the medication may be in a form as described, being a compressed pressurized aerosol formulation often in a form known as metered-dose inhalers or MDIs. Alternatively, powder or other solid formulations or even liquids or gases may be provided and dispensed at a set dose. Liquids may be of a volatile nature. Separate individual doses of medication may be provided in a capsule or similar form and adapted for release in devices often referred to as medihalers. These devices may have rotatable vanes which are activated by a patient breathing in, thereby distributing the medication into the airstream. In some arrangements, a fine powder may be simply breathed into the lungs after separation into individual particles and entrainment in inspiratory gases.
While these developments have been of tremendous benefit to sufferers of diseases that lend themselves to effective self-medication, there has been an ongoing problem of patients either forgetting their medication canisters or mistakenly believing they are stored somewhere, such as a handbag or sports bag, only to find the medication is not available for use when required. This can have serious consequences in the event of a sudden severe onset of disease signs and symptoms. The problem of effectively and safely storing medication canisters is exaggerated in sporting activities where clothes are often designed for the specific requirements of the sport being undertaken, but with no provision of secure pockets or pouches. Even when pockets are provided, the presence of a hard object carried in such a pocket may be uncomfortable, irritating or even performance-restricting in a competitor. The problems may be pronounced in activities, such as snorkeling, scuba diving, orienteering and mountaineering where a sufferer of a condition may find themselves a considerable distance from a support base with little else other than gear required for the activity.
Use in harsh environments or inclement conditions, such as rain and snow, may lead to ingress of moisture and other contaminants, such as mud, dust, sand, vegetable matter or other materials that may damage a medication device or present a risk to the user.
U.S. Pat. No. 4,130,116 (“Cavazza”) describes a pocket device into which a spray can may be inserted. Mechanical means are provided wherein the device may be kept in a closed position when not in use but can be activated to expose the nozzle portion of the spray can to permit utilization of the can. The disclosure is to two halves that slide with respect to each other along guides located along borders of the lateral walls. There is no indication that the device is sealed against moisture and, in its operation, a wide aperture is presented to the environment both at the first nozzle end and second actioning end. The application of the device is therefore somewhat limited, particularly in inclement environments, such as are often encountered during sporting activities, particularly waterborne sports and endurance type activities.
CA 2,379,137 (“Pharmaceutical Discovery Corporation”) describes a dry powder inhaler having an intake section, a mixing section and a rotatable mouthpiece. The device is relatively complex, although it does include a storage section for holding an extra medicament capsule. The device is particularly directed towards controlling a rate of airflow using a tapered piston rod and spring and one or more bleed-through orifices. It may also include a feedback module to generate a tone indicating when a proper rate of airflow has been achieved. Again, there is no indication that this device is environmentally sealed. It appears to be relatively bulky and complex in operation. Further, a person in shock or respiration distress may be unable to provide the necessary inspiratory effort.
U.S. Pat. No. 5,497,764 (“Ritson”) is directed to a portable battery powered handheld system for releasing a controlled dose of aerosol medication for inhalation by a patient. The device includes a durable body and a medication cassette inserted in the durable body. Although the disclosure is to an electronic and relatively complex apparatus, it does disclose formation of a cassette for insertion inside the device which is constructed so that it can be used as a conventional, manually actuated metered dose inhaler device apart from the durable body. This, however, requires removal of the device from the body for its function. When housed in the durable body, the operation of the device is relatively complex. The pharmaceutical formulations may be a liquid or powder formulation. The device is not environmentally sealed. It appears relatively complex and is predominantly electronic.
BE 905189 (“Glaxo Group Ltd”) is directed to a device for administering medicaments in solid finely divided form to patients. The device is relatively complex, having a housing and a tray with a support disk provided on the tray and adapted to receive a carrier which, in turn, carries the medication. A plunger is operable to penetrate the container after it is aligned with the plungers. Air enters through the device and is inhaled.
DE 4028387 (“Bechter”) discloses a cover device that dissembles to provide a breathing mask with free space over the nose and chin. It is therefore relatively large. It is designed in one embodiment as a breathing mask for use with inhalation apparatus.
The device is therefore developed as a breathing mask for use in conjunction with an inhalation apparatus.
WO 01/00263 (“Inhale Therapeutic Systems”) discloses an arrangement in which air is prevented from entering the lungs until a prescribed threshold of vacuum is obtained by a user. Air is then abruptly permitted to flow to the lungs. This may be contradicted in a subject in shock or respiratory distress.
WO 1995/028192 (“Dura Pharmaceuticals”) describes a dry powder medicine inhaler having a housing and a mouthpiece. An impeller is rotatably mounted on a pin to rotate within the aerosolizing chamber. Radial inlets pass through the housing and enter substantially tangentially into the chamber. A charging plunger is pressed downward in operation against the bias of a spring to press a full dose of powdered medicine into the chamber. The plunger is then held against the spring bias during operation and forms a top portion of the wall of the chamber. A dosage cartridge may be placed on pegs in an open area. A hold down lever is then pivoted to retain the cartridge and lock a mouthpiece in its operative position. A multi-dose medicine containing cartridge may be used. The impeller is driven at high speed by a motor. The impeller acts as a centrifugal air pump drawing air through the inlet and is driven by a high speed electric motor which relies on one or a pair of batteries. Again, this device relies on battery input. However, the device can be operated by inhalation from the user alone. The device does not appear to be environmentally sealed against moisture in particular. Further, in both embodiments, it is a relatively complex device and is restricted to use of powder.
WO 2000/018455 (“Glaxo”) provides an inhalation device suitable for dispensing respiratory medication. It has a cover to prevent build-up of dust on the mouthpiece but is not sealed against water. It also has a geared and relatively complex actuator for use in operation.
WO 2002/004043 (“Vapotronics”) discloses an inhaler to deliver medicament or other fluids in droplet form and during inhalation. The inhaler has an airflow conduit assembly extending through the housing, a mouthpiece which is fluidly interconnectable with the airflow conduit assembly and a droplet ejection cartridge housing. A droplet ejection is removably disposed within the cartridge housing. The airflow conduit assembly may include a plenum into which air is initially drawn. The mouthpiece is removable and stowable on the device. A droplet ejection cartridge is provided which includes a medicament reservoir, a plurality of droplet ejection orifices and at least one droplet ejection actuator. The droplet ejection cartridge includes a PCB interface on one of its sides for interfacing with a printed circuit board which controls the operation of the inhaler. Pressure sensors are used to activate the device and a nozzle region is provided which includes a plurality of droplet ejection orifices. Each droplet ejection orifice has its own resistor, such as there is a one-to-one relationship for dispensing the medicament. The device is therefore a complex electronic arrangement and relies on electric power in use. It may have limited application in harsh environments.
As noted, in inclement circumstances, the risk of contamination may be significant. A sealed, safe and robust storage arrangement would be of advantage, particularly if designed for easy and effective use when required.
Use of therapeutics in emergency situations may present different risks which can be highly serious. Delivery of an analgesic, for example, requires an arrangement that is robust, reliable and easy to operate. This is particularly the case in the circumstance of self-administration where a user may be, at least partially, incapacitated by injury or people lending assistance may be untrained in first aid.
Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that this prior art forms part of the common general knowledge in any country.